Canalicular plug, method and kit for treating dry eye

ABSTRACT

A plug for occluding an ocular canaliculus comprises a cylindrical body member having a first outer diameter. The cylindrical body member is provided along an external surface with at least one outwardly extending projection having a second outer diameter greater than the first outer diameter and larger than an inner diameter of an ocular canaliculus. The first outer diameter of the plug is typically less than and approximately equal to the inner diameter of the canaliculus.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of application Ser. No. 15/536,466 filedJun. 15, 2017 as a U.S. National Stage of International Application No.PCT/US2015/063917 and now issued as U.S. Pat. No. 11,051,982. Thisapplication also claims the benefit of U.S. Provisional PatentApplication No. 62/093,271 filed Dec. 17, 2014.

BACKGROUND OF THE INVENTION

This invention relates to the treatment of dry eye syndrome. Moreparticularly, this invention relates to a canalicular plug system, amethod for treating dry eye syndrome and/or an associated kit.

Keratoconjunctivitis sicca (KCS), also called dry eye syndrome (DES) orkeratitis sicca, is an eye disease characterized by eye dryness. Eyedryness arises from either decreased tear production or increased tearfilm evaporation.

The lacrimal canaliculi, also known as the lacrimal canals, are smallchannels that commence with tiny openings, termed puncta lacrimalia.There is one canaliculus at each eyelid an upper canaliculus and a lowercanaliculus, each having a dog leg shape. Each canaliculus starts at therespective punctum with a short upwardly or downwardly extending segmentwhich communicates with a longer horizontally extending segment that isconnected at an inner end to a lacrimal sac.

There are millions of patients with dry eye problems. Many can be helpedwith plugging of the punctum or canaliculi (all 4 of them). What is notappreciated by many physicians is that plugging of the punctum withexternal plugs can sometimes increase irritation and dry eye symptoms.Also, a good number of patients, about a third, loose their plugs withinthe first 3-4 weeks and the plugs have to be replaced. The mostimportant advantage of plugs is that they are visible on examination. Toachieve the desired benefit from plugs, i.e., occlusion, one mustocclude both upper and lower ducts. However, most of these patients willhave epiphora, or spill over from too much tears if the treatmentconsists of external punctum plugs. It is an all or nothing situation atpresent.

OBJECTS OF THE INVENTION

It is an object of the present invention to provide an improved methodand or apparatus for treating dry eye syndrome.

It is a more particular object of the present invention to provide animproved and effective lacrimal or canalicular plug for insertion intoan ocular canaliculus.

Another object of the present invention is to provide a method forcustomizing the treatment of tear deficient dry eye syndrome with anefficient method of reducing the tear drainage.

A further object of the present invention is to provide a kit that isuseful in carrying out the method in a titratable manner.

These and other objects of the present invention will be apparent fromthe descriptions and drawings herein. Although every object of theinvention is attainable by at least one embodiment of the invention,there is not necessarily any single embodiment that achieves all of theobjects of the invention.

SUMMARY OF THE INVENTION

A customized tear duct occlusion system as described herein below willafford the physician and patients benefits without the side effects ofconventional procedures which can lead to canaliculitis, chronicinfections or even dacryocystitis, requiring surgical intervention.Lacrimal or canalicular tear-occluding plugs as described below areindwelling intra canalicular plugs, that is, the plugs are designed forinsertion well beyond the punctum and deep into the canaliculi. Theplugs are preferably made from a hydrophilic material that thickenssufficiently to block the drainage of tears but also dissipates within5-6 months' time, using a smart material. The plugs preferably have acorrugated outer surface to help retention and further reduce outflow oftears.

In a customized tear occlusion technique, the upper canaliculus isprovided with a plug having a particular diameter and length to fullyocclude the upper canaliculus for a specified duration. In the testingor calibration procedure, the lower canaliculus is occluded startingwith a half length plug and the patient returns in 2-3 weeks to assesschange in tear meniscus or volume and symptoms. Depending on findings,the physician places an additional ¼ sized plug and checks the patientagain in 2-3 weeks. This is repeated once or twice until sufficientplugging of the canaliculus is achieved to reduce outflow to a specificdegree for that individual patient just short of overflow. Once thesesizes are established for the lower canaliculus, this composite of plugsare left in for the extended duration until they dissipate or dissolvein 5-6 months. This composite or total length customized plug is thenused to insert into the lower canaliculus in each subsequent occlusiontherapy session required by the patient. For the upper canaliculus, thesame sized plug used initially is also replaced to maintain optimum tearretention. This now customized degree of occlusion is utilized insubsequent extended periods of about 5-6 months for relief of symptomsof dry eye syndrome and for permitting contact lens use by the patient.

A plug for occluding a canaliculus comprises a cylindrical body memberhaving a first outer diameter. The cylindrical body member is providedalong an external surface with at least one outwardly extendingprojection having a second outer diameter greater than the first outerdiameter and larger than an inner diameter of an ocular canaliculusPreferably the first outer diameter of the plug is less than andapproximately equal to the inner diameter of the ocular canaliculus orlacrimal duct.

The projection preferably takes the form of an annular rib. Where theplug has an extended length, multiple annular ribs may be axiallystaggered along an external surface of the plug. The ribs are typicallycoaxial with an axis of the cylindrical body member.

In a preferred embodiment, the annular rib has a smoothly arcuate outersurface, that is, without points or sharp edges. The rib has, forinstance, a substantially semi-circular cross-section or partiallycircular outer perimeter.

The cylindrical body of the plug may be provided on at least one endwith a formation taken from the group of a recess and an additionalprojection extending axially from the cylindrical body member. Therecess or projection mates with a projection or recess on an end ofanother canalicular plug to thereby prevent relative rotation of the twoplugs once they are properly deployed in a canaliculus (usually a lowerduct) of a patient.

The recess may be a slot and the additional projection a geometricallysimilar planar or plate-shaped extension of the cylindrical body member.

A kit for use in treating dry eye syndrome comprising a container and aplurality of plugs disposed in the container, each of the plugs having across-section accommodating insertion of the respective plug in acanaliculus of a human patient. At least one of the plugs has a firstlength, at least a second one of the plugs has a second length a firstfraction of the first length, and at least a third one of the plugs hasa third length a second fraction of the first length. The second andthird plugs may have the same length, for instance, a third or a quarterof the length of the first plug. The second and third plugs may be ofdifferent lengths, for instance, one a half and the other a quarter ofthe length of the first plug.

The plugs are titrating or customizing plugs of staggered sizes selectedfor a step wise customization process wherein the total length ofseveral plugs placed in a canaliculus (typically the lower of the twoducts for a given eye) is incrementally increased over a period ofseveral weeks to determine an optimal plug length for the patient. Atthe end of the titrating or customizing period, the customization ortesting plugs disposed in the canaliculus at that point are left in thecanaliculus until they dissipate or dissolve over an extended wearperiod of 5-6 months. The composite length, i.e., the sum of the lengthsof the titrating segments, is noted and, once the original set of plugseffectively dissolve or dissipate, a plug of like size is selected fromthe kit and is inserted into the lower canaliculus to continue theocclusion process and thereby increase the tear margin of that eye for anetted extended period or for so long as the patient desires this formof therapy for their dry eye symptoms or contact lens wearing option.

The kit may include an extended wear canalicular plug of predetermineddimensions for completely occluding the upper canaliculus of the eyebeing treated. The kit may further include a set of second extended-wearcanalicular plugs of different lengths each equal to a composite lengthof a respective set of the titrating or calibration plugs. One of thesecond extended-wear canalicular plugs is selected for insertion intothe lower canaliculus upon determination of an optimal length fortreating dry eye symptoms without inducing epiphora. As mentioned above,the second extended-wear canalicular plugs are inserted into the lowercanaliculus upon dissolution or dissipation of previously insertedplugs.

Each of the plugs in the kit typically includes a cylindrical bodymember having a first outer diameter preferably less than andapproximately equal to an inner diameter of an ocular canaliculus orlacrimal duct. The cylindrical body member is provided along an externalsurface with at least one outwardly extending projection having a secondouter diameter greater than the first outer diameter and larger than theinner diameter of the canaliculus.

The projection preferably but not necessarily takes the form of anannular rib. The rib may be one of a plurality of annular ribspositioned in a staggered locations along an external surface of thecylindrical body member, all of the annular ribs being coaxial with anaxis of the cylindrical body member. Any given rib preferably has asmoothly arcuate outer surface, no points or edges, for instance, wherethe rib has a substantially semi-circular cross-section.

Each of the plugs in the kit may be provided on at least one end with aformation taken from the group of a recess and an additional projectionextending axially from the respective cylindrical body member. Therecess is exemplarily a slot and the additional projection a planar orplate-shaped extension of the respective cylindrical body member. Theslot or recess mates with a formation on another plug or on a deploymenttool. In the former case the mating formations prevent undue relativerotation between adjacent plug elements, while in the latter case themating formations enable or facilitate deployment operations via use ofthe tool.

Thus, the kit may include an insertion tool configured for rotating adeployed plug that is disposed in an ocular canaliculus. The toolincludes a distal tip with a geometric configuration that is rotativelylockable for the deployed plug.

A method for treating dry eye syndrome comprises inserting a firstcanalicular plug into an upper canaliculus of a patient's eye, the firstcanalicular plug having a first length. The method further comprisescarrying out a testing or calibration process to determine an optimallength of a second canalicular plug for a lower canaliculus of thepatient's eye. The titrating or customizing process includes inserting afirst test or titrating plug into a lower canaliculus of the patient'seye, the first titrating or customizing plug having a second length, andafter a first testing period of predetermined duration during which tearaccumulation in the patient's eye is monitored, inserting a secondtitrating or calibration plug into the lower canaliculus of thepatient's eye and adjacent the first test or customizing plug. Thesecond titrating or calibration plug has a third length that is afraction of the second length. The method optionally includes insertingadditional titrating or customizing plugs of respective lengths lessthan the second length and monitoring eye moisture. Upon a determinationthat tear accumulation in the patient's eye is satisfactory, allinserted titrating or customizing plugs are kept in the lowercanaliculus of the patient's eye and thereafter, after the titratingplugs have dissolved, a new plug with a composite length equal to thecombined lengths of the inserted titrating plugs is subsequentlyinserted into the lower canaliculus of the patient's eye. Thus, theoptimal length is a total length that is at least approximately equal toa sum of the lengths of a set of the titrating or customizing plugsactually inserted into the lower canaliculus of the patent's eye.

While it may be the case that the optimal length of the secondcanalicular plug is equal to the combined lengths of all the titratingor customizing plugs that were inserted into the lower canaliculusduring the titrating or customizing procedure, in some cases, ifepiphora is induced upon insertion of the last test or calibration plug,then the composite length of all the inserted test or calibration plugsis too great and a shorter length is required for the second orsubsequent length of choice to be inserted into the canaliculus.

The inserting of the second titrating or customizing may includerotatively locking the second test or calibration plug and the firsttest or calibration plug to one another by engaging cooperating elementson adjacent ends of the first test or calibration plug and the secondtest or calibration plug with one another.

The inserting of any given canalicular plug into a canaliculus of apatient's eye may include both translating the plug along the respectivecanalicular canal and rotating the plug. The method may be carried outby using a tool where the rotation is causally linked to thetranslation, for instance, where the tool includes a pair of coaxialtubes, one having a spiral camming slot and the other a lug that isslidably seated in the slot.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side elevational view of a canalicular plug fordeployment in the canaliculus of a patient suffering dry eye syndrome.

FIG. 2 is a schematic right side elevational view of the canalicularplug of FIG. 1.

FIG. 3 is a schematic left side elevational view of the canalicular plugof FIG. 1.

FIG. 4 is a schematic longitudinal cross-sectional view taken along lineIV-IV in FIG. 2.

FIG. 5 is a schematic side elevational view of a smaller or shortercanalicular plug for deployment in a canaliculus of a patient sufferingdry eye syndrome, for use in a titrating or customizing process todetermine an optimal plug size.

FIG. 6 a schematic longitudinal cross-sectional view taken parallel tothe plane of the drawing in FIG. 5.

FIG. 7 is a schematic side elevational view of an even smaller orshorter canalicular plug for deployment in a canaliculus of a patientsuffering dry eye syndrome, for use in a titrating or customizingprocess to determine an optimal plug size.

FIG. 8 a schematic longitudinal cross-sectional view taken parallel tothe plane of the drawing in FIG. 7.

FIG. 9 is a schematic representation of a kit for treating dry eyesymptoms.

FIG. 10 is a diagrammatic partial end elevational view, on an enlargedscale, of an ocular plug with a slot and undercuts for facilitatinginsertion.

DETAILED DESCRIPTION

As illustrated in FIGS. 1-4, a plug 20 for occluding a canaliculuscomprises a cylindrical body member 22 having a first outer diameter d1.Cylindrical body member 22 is provided along a cylindrical external orouter surface 24 with at least one outwardly extending projection 26unitary with body member 22 and having a second outer diameter d2 thatis greater than diameter d1 and larger than an inner diameter of anocular canaliculus. Preferably outer diameter d1 is less than andapproximately equal to the inner diameter of the ocular canaliculus orcanalicular duct.

Canalicular plug 20 may serve as a long-term or extended-wear plug,which once implanted remains in the canaliculus for months at a time. Inthat case plug 20 may be longer, with three or more outwardly extendingprojections 26 spaced from one another and flanked by sections ofcylindrical external or outer surface 24 (see also plugs 84 in FIG. 9).Alternatively, plug 20 may serve as a titrating or customizing plug foruse in a method to determine an optimal length of an extended wearcanalicular plug. Typically, an upper canaliculus of a patient is fittedwith a standard size long-term plug (or one of a plurality of standardsize plugs) that substantially completely occludes the uppercanaliculus, while a testing or calibration process is used on theassociated lower canaliculus to determine a plug length that effectivelyreduces dry eye symptoms but does not lead to epiphora.

Projection 26 preferably takes the form of an annular rib having asmoothly arcuate outer surface, that is, without points or sharp edges.Rib 26 has, for instance, a cross-section with an outer boundary that isa section of a circle. Where plug 20 has an extended length, multipleannular ribs 26 may be axially staggered along external surface 24 ofthe plug. Ribs 26 are typically coaxial with an axis 28 of cylindricalbody member 22.

Cylindrical body member 22 of plug 20 may be provided on at least oneend with a formation facilitating insertion of the plug into acanaliculus. If the plug is a test or calibration plug, the formationalso serves to rotationally lock the plug to an adjacent plug during thetesting process. As illustrated in FIGS. 1-4, a test or calibration plug20 may include a first formation in the form of a slot-shaped recess 30at one end and a second formation in the form of a plate-shapedprojection 32 at an opposite end. Recess 30 and projection 32 aresymmetric about axis 28 and modularly sized: projection 32 is slightlysmaller than recess 30 and geometrically similar thereto so that aprojection 32 on one canalicular plug of a set of plugs can insert intothe recess 30 of another plug. Recesses 30 and projections 32 thus matewith one another to thereby prevent relative rotation of two adjacentplugs once the same are properly deployed in a canaliculus (usually alower duct) of a patient, typically in a testing or calibration process.

As illustrated in FIGS. 5 and 6, an intermediately sized plug 40 forpartially occluding a lacrimal duct or canaliculus in a testing ormeasurement process together with one or more additional test orcalibration plugs comprises a cylindrical body member 42 having a firstouter diameter d1′. Cylindrical body member 42 is provided along anexternal surface 44 with two outwardly extending projections 46 a and 46b each having a second outer diameter d2′ that is greater than diameterd1′ and larger than an inner diameter of an ocular canaliculus orlacrimal duct. Preferably outer diameter d1′ is less than andapproximately equal to the inner diameter of the ocular canaliculus orlacrimal duct (typically a lower canaliculus) being fitted for along-term plug.

Projections 46 a and 46 b are preferably each in the form of an annularrib having a smoothly arcuate outer surface, that is, without points orsharp edges at least along the outermost regions that come into contactwith the inner surface of the canaliculus. Ribs 46 a has, for instance,a cross-section with an outer boundary that is a section of a circle.Rib 46 b is truncated. While rib 46 b has a sharp terminal edge 47, theedge preferably has a diameter sufficiently smaller than diameter d2′ toavoid undue irritation of the lacrimal duct. Alternatively, edge 47 maybe blunted or rounded during the manufacturing process. Ribs 46 a and 46b are coaxial with an axis 48 of cylindrical body member 42.

Cylindrical body member 42 of plug 40 is provided on one end with afirst formation in the form of a slot-shaped recess 50 and on anopposite end with a second formation in the form of a plate-shapedprojection 52. Recess 50 and projection 52 are symmetric about axis 48and modularly sized: projection 52 is slightly smaller than recess 30and geometrically similar thereto so that projection 52 can insert intorecess 30 of a prior inserted test plug 20. Alternatively, projection 32may face outwardly upon a seating of test plug 20 in a patient'scanaliculus and be received in slot 50 of a subsequently inserted testplug 40. Recesses 30, 50 and projections 32, 52 are thus modularlydesigned to mate with one another to thereby prevent relative rotationof two adjacent test or calibration plugs 20, 40 once the same areproperly deployed in a canaliculus (usually a lower duct) of a patient,typically in a testing or calibration process. This rotational lockingserves in part to prevent drifting of the separate titrating orcalibration plugs during the testing period and also during an extendedwear period thereafter.

Canalicular plug 40 serves as a testing or calibration plug for usetogether with other titrating plugs such as test or calibration plug 20in a method to determine an optimal length of a long-term or extendedwear canalicular plug typically for a lower canaliculus of a patient.Typically, in such a method outer diameters d1′ and d2′ of plug 40 arerespectively equal to outer diameters d1 and d2 of plug 20. Canaliculartest plug 20 is inserted into the lower canaliculus of a patient, beforeor after the insertion of a longer plug (with a greater number ofannular ribs 26) into the associated upper canaliculus. The patientwears the two plugs for a predetermined period of time, typically two orthree weeks, and then provides a report on the effectiveness of theocclusion of the canaliculi. If the dry eye symptoms persist, test orcalibration plug 40 is then inserted into the lower canaliculus of thepatient adjacent plug 20 with projection 52 of plug 40 inserted intorecess 30 of plug 20. During a subsequent monitoring period ofpre-established duration, typically two to three weeks, the patientwears the two plugs 20 and 40 in the lower canaliculus and thereafterreports on eye dryness to the doctor. If the dry eye symptoms areobviated, without epiphora, then the test plugs 20 and 40 are typicallyretained in the lower canaliculus for an extended-wear period of up to5-6 months. In subsequent treatments, single extended-wear plugs areinserted into the lower canaliculus, where the extended-wear plugs havea length equal to the sum of the lengths of the plugs 20, 40 that remainin the patient after the test period. If the test or calibration phaseends with the patient experiencing epiphora, then the subsequentextended-wear plugs selected may have a length somewhat shorter than thecombined lengths of the inserted or deployed test plugs.

Although not necessary or advisable, the titrating or test plugs may beremoved at the end of the test or calibration phase and the patientprovided in the lower canaliculus with a long-term plug of a lengthabout equal to the combined lengths of the test plugs 20 and 40. If thedry eye symptoms persist with plugs 20 and 40 disposed in the lowercanaliculus, another test or calibration plug 60 (FIGS. 7 and 8) maythen be inserted into the lower canaliculus of the patient over plugs 20and 40 so that the test plugs 60 and 40 are adjacent to one another.

As illustrated in FIGS. 7 and 8, test plug 60 comprises a cylindricalbody member 62 having a first outer diameter d1′. Cylindrical bodymember 62 is provided along an external surface 64 with one outwardlyextending projection 66 having a second outer diameter d2′ that isgreater than diameter d1′ and larger than an inner diameter of an ocularcanaliculus. Preferably outer diameter d1′ is less than andapproximately equal to the inner diameter of the ocular canaliculus(typically a lower canaliculus) being fitted for a long-term plug.

Projection 66 is preferably an annular rib having a smoothly arcuateouter surface, that is, without points or sharp edges at least along theoutermost regions that come into contact with the inner surface of thecanaliculus. Rib 66 has, for instance, a cross-section with an outerboundary that is a section of a circle. Rib 66 is coaxial with an axis68 of cylindrical body member 62.

Cylindrical body member 62 of plug 60 is provided on one end with afirst formation in the form of a slot-shaped recess 70 and on anopposite end with a second formation in the form of a plate-shapedprojection 72. Recess 70 and projection 72 are symmetric about axis 68and modularly sized: projection 72 has a size and shape selected toenable insertion of projection 72 into recess 30 or 50 of a priorinserted test plug 20 or 40. Alternatively, if projection 32 or 52 facesoutwardly upon a seating of test plug 20 or 40 in a patient'scanaliculus, projection 32 or 52 is received in slot 70 of subsequentlyinserted test plug 70. Thus, all recesses 30, 50, 70 and projections 32,52, 72 are modularly adapted to mate with one another, which serves inpart to prevent relative rotation of two adjacent test or calibrationplugs 20, 40, 60 once the same are properly deployed in a canaliculus(usually a lower duct) of a patient, typically in a testing orcalibration process. The rotational locking serves to hold the test orcalibration plugs 20, 40, 60 in place relative to one another.

In summary, a method for treating dry eye syndrome contemplates theinsertion of a long-term or extended-wear plug in one canaliculus(usually an upper) and the fitting of the other canaliculus (lower,usually) by testing the effectiveness of a series of test plug sets eachhaving a respective combined or total plug length. In a typicalprocedure, the lower canaliculus of a patient is fitted with a series oftest plug sets each incrementally longer than a prior test plug set.Should any particular set of deployed test plugs result in continued dryeye symptoms, then any long-term or extended-wear plug selected for thepatient will be longer than the total plug length of the particular testset. Should any particular set of test plugs result in undue epiphora,then long-term or extended-wear plugs selected for the patient may beshorter than the total length of the test plugs of that test set.

As depicted in FIG. 9, a kit 80 for use in treating dry eye syndromecomprises a container 82 and a plurality of plugs 84 disposed in thecontainer, each of the plugs having a cross-section accommodatinginsertion of the respective plug in a canaliculus of a human patient.Plugs 84 are independently and individually deployable unitary rigidunits of predetermined fixed shape and dimensions. At least one plug 86in the kit has a first length s1, at least a second plug 88 has a secondlength s2 which is a fraction of the first length s1, and at least athird plug 90 has a third length s3 which is a different fraction of thefirst length s1. The second and third plugs 88 and 90 may have a commonlength (s2=s3), for instance, a third or a quarter of the length s1 ofthe first plug 86. Preferably, the second and third plugs 88 and 90 areof different lengths, for instance, one a half and the other a quarterof the length s of the first plug 86. As described above, plugs 86, 88,and 90 are test or calibration plugs of staggered sizes adapted for astep wise titration or customization process wherein the total length ofseveral plugs placed in a canaliculus (typically the lower of the twoducts for a given eye) is incrementally increased over a period ofseveral weeks to a few months to determine an optimal plug length forthe patient. At the end of the testing or calibration period, the finalset of customization or testing plugs is typically allowed to remain inthe patient's lower canaliculus and subsequently, after dissolution ofthe test plugs, a long-term plug is inserted having a length equal tothe sum of the lengths of the test plugs determined as optimal fortreating dry eye symptoms of the patient. The long-term plug may be cutfrom a plug blank 92 that has a predetermined standard maximum length.Preferably, kit 80 includes a set of long-term canalicular plugs 94 ofdifferent predetermined lengths each equal to a composite length of arespective set of the test or calibration plugs 84. One of the long-wearcanalicular plugs 94 is selected for insertion into the lowercanaliculus after determination of an optimal length for treating dryeye symptoms without inducing epiphora.

Kit 80 may additionally include one or more long-wear canalicular plugs96 of predetermined dimensions for completely occluding the uppercanaliculus of the eye being treated. Typically, plugs 96 have a lengthsufficiently large to ensure complete occlusion of the uppercanaliculus.

Kit 80 may further include one or more additional sets of test orcalibration plugs 98 of staggered lengths which have a larger basediameter d3, annular sealing rings or projections 100 of larger outerdiameters d4, and a different selection of lengths.

Each of the plugs 86, 88, 90, 92, 94, 96, 98 in kit 80 includes, asdiscussed above with reference to FIGS. 1-8, a cylindrical body memberhaving a base outer diameter less than and approximately equal to aninner diameter of an ocular canaliculus. Each plug 86, 88, 90, 92, 94,96, 98 is formed along an external surface of the respective cylindricalbody member with at least one outwardly extending preferably annularprojection having an outer diameter greater than the base diameter ofthe cylindrical body member and larger than the inner diameter of thecanaliculus. As discussed above, the projections preferably but notnecessarily take the form of annular ribs.

Each of the test or calibration plugs 86, 88, 90, 98 in the kit 80 maybe provided on each end with a recess (e.g., slot) or an axialprojection (e.g., tongue or plate), while each of the long-term plugs,92, 94, 96 might bear such a formation on only one end, that is, theouter end, for facilitating insertion and optional removal procedures.The recesses and projections on the test or calibration plugs 86, 88,90, 98 mate with complementary formations on other test or calibrationplugs 86, 88, 90, 98, preventing or reducing undue relative rotationbetween adjacent plug elements. The end formations on the long-termplugs, 92, 94, 96 cooperate with a deployment tool 102 for facilitatinginsertion and optional retraction procedures. Tool 102 is configured forrotating a deployed plug (test or long-term) that is disposed in anocular canaliculus. Tool 102 includes a flexible shaft 103 and a distaltip 104 with a geometric configuration that is rotatively lockable toand removable from the deployed plug. Tool tip 104 may include one ormore fingers or nubs 106 that are alternately insertable into andremoval from respective undercuts 108 and 110 (FIG. 10) in an ocularplug 112. Undercuts 108 and 100 communicate with a slot 114 that receivethe tip 104 of tool 102. Fingers or nubs 106 and undercuts 108 and 110enable the application of a tensile force on the canalicular plugs, sothat the plugs are entrained to the tool and more easily extractiblefrom a canaliculus. It is to be noted that the removal of plugs islikely rare and carried out only under unusual circumstances.

A method for treating dry eye syndrome utilizing kit 80 comprisesinserting a selected long-term canalicular plug 96 into an uppercanaliculus of a patient's eye. The method further comprises carryingout a titrating or calibration process to determine an optimal length ofa long-term canalicular plug for a lower canaliculus of the patient'seye. The testing or calibration process includes inserting a first testor calibration plug 86, 88, or 90 or one of plugs 98 into the lowercanaliculus of the patient's eye. Thereafter, the patient wearslong-term plug 96 and the first test plug 86, 88, 90, 98 during a firsttesting period of predetermined duration, typically a two to threeweeks, during which the patient monitors tear accumulation in his or hereye. If necessary, that is, if dry eye symptoms persist, a second testor calibration plug 86, 88, 90, 98 is inserted into the lowercanaliculus of the patient's eye and adjacent or over the first test orcalibration plug 86, 88, 90, 98. The second test or calibration plugtypically has length that is a fraction of the length of the first testor calibration plug. (However, a set of modular calibration plugs of thesame length may be used in the titrating or fitting process.) Thepatient then monitors eye moisture for another period of typically twoto three weeks. Upon a determination that tear accumulation in thepatient's eye is satisfactory, the inserted test or calibration plugs86, 88, 90, 98 are allowed to remain in the patient's canaliculus for anextended period of up to 5 or 6 months. Alternatively, but typicallyunnecessary, the test or calibration plugs are removed from the lowercanaliculus of the patient's eye and replaced with a final canalicularplug cut from blank 92 or selected from plugs 94, this final canalicularplug having a length that is at least approximately equal to a sum ofthe lengths of the test or calibration plugs 86, 88, 90, 98 thatprovided a satisfactory or optimal correction of the patient's dry eyesymptoms.

In general, it is contemplated that the fitting of one canaliculus of anupper and lower pair is achieved by a series of test plug sets. Along-term plug has a length selected in accordance with the results ofthe test plug sets. If dry eye symptoms persist with any one test plugset, then the length of any long-term plug for the patient will belonger than the combined lengths of that test plug set. Conversely, ifepiphora results with any selected test plug set, then the length of anylong-term or extended-wear plug will be shorter than the combinedlengths of that selected test plug set. It is possible to select alength of a long-term plug on the basis of an interpolation where onetest plug set results in dry eye symptoms and a next-longer test plugset results in epiphora.

The inserting of the long-term and calibration plugs and the removing ofthe calibration or fitting plugs may be implemented by rotating theplugs during the exertion of a pushing or pulling force on the plugs.

The canalicular plugs described herein comprise hydrophilic andbiodegradable materials known in the medical industry. Examples includealiphatic polyesters such as polyglycolic acid (PGA), polylactic acid(PLA), Poly ε-caprolactone (PCL), etc.; polyaminoacids, and co-polymersof polyamino acids.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. A method for treating dry eye syndrome,comprising: (a) inserting a first canalicular plug into an uppercanaliculus of a patient's eye, said first canalicular plug having afirst length; (b) carrying out a testing or calibration process todetermine an optimal length of a second canalicular plug for a lowercanaliculus of the patient's eye, said testing or calibration processincluding (i) inserting a first test or calibration plug into a lowercanaliculus of the patient's eye, said first test or calibration plughaving a second length, (ii) after a first testing period ofpredetermined duration during which tear accumulation in the patient'seye is monitored, inserting a second test or calibration plug into thelower canaliculus of the patient's eye and adjacent said first test orcalibration plug, (iii) optionally repeating steps (i) and (ii) usingadditional test or calibration plugs of respective lengths, and (c)thereafter inserting a long-term or extended-wear canalicular plug ofsaid optimal length into the lower canaliculus of the patient's eye,said optimal length being a total length that is at least approximatelyequal to a sum of the lengths of a set of the test or calibration plugsdisposed in the lower canaliculus of the patient's eye upon terminationof said testing or calibration process.
 2. The method defined in claim 1wherein the inserting of said second test or calibration plug includesrotatively locking said second test or calibration plug and said firsttest or calibration plug to one another by engaging cooperating elementson adjacent ends of said first test or calibration plug and said secondtest or calibration plug with one another.
 3. The method defined inclaim 1 wherein the inserting of any one of the first and secondcanalicular plug into a canaliculus of a patient's eye includes rotatingthe first or second canalicular plug respectively.
 4. The method definedin claim 1 wherein said second test or calibration plug has a thirdlength that is a fraction of said second length.
 5. A method fortreating dry eye syndrome, comprising: (a) inserting a first canalicularplug into an upper canaliculus of a patient's eye, said firstcanalicular plug having a first length; (b) carrying out a testing orcalibration process to determine an optimal length of a secondcanalicular plug for a lower canaliculus of the patient's eye, saidtesting or calibration process including (i) test or calibration plugsinto a lower canaliculus of the patient's eye, said test or calibrationplugs having respective lengths and (ii) monitoring tear accumulation inthe patient's eye in response to different cumulative lengths of saidtest or calibration plugs, and (c) thereafter inserting a long-term orextended-wear canalicular plug of said optimal length into the lowercanaliculus of the patient's eye, said optimal length being a totallength that is at least approximately equal to a sum of the lengths of aset of the test or calibration plugs disposed in the lower canaliculusof the patient's eye upon termination of said testing or calibrationprocess.
 6. The method defined in claim 5 wherein the inserting of saidtest or calibration plugs includes rotatively locking at least two ofsaid test or calibration plugs to one another by engaging cooperatingelements on adjacent ends of said at least two of said test orcalibration plugs with one another.
 7. The method defined in claim 5wherein the inserting of any one of the first and second canalicularplug into a canaliculus of a patient's eye includes rotating the firstor second canalicular plug respectively.
 8. The method defined in claim5 wherein said test or calibration plugs have different lengths.